textproduct: Albany

WHAT HAS CHANGED

Confidence remains very high on a low pressure system to bring rain, snow and gusty winds Thursday night through Friday, though the time arrival of this system is later than the previous forecast.

KEY MESSAGES

1. Mainly dry conditions are expected through Thursday with temperatures trending to near normal values.

2. A storm system will bring a widespread rainfall and gusty winds Thursday night through Friday morning with falling temperatures, strong winds and rain changing to snow Friday afternoon through Friday night.

3. A clipper system may bring a period of snow or a rain/snow mix to parts of the area next weekend.

DISCUSSION

KEY MESSAGE 1... Generally zonal flow will be in place today through Thursday with high pressure located south of the region. This will result in a period of mainly dry weather with the exception being Wednesday afternoon into Wednesday evening as a passing upper level shortwave brings mixed rain and snow showers mainly for areas north and west of the Capital District and into the southern Greens. Any snow accumulations will be minimal, generally less than 1 inch. After a prolonged period of below normal temperatures, temperatures will rebound back closer to normal for Wednesday and Thursday.

KEY MESSAGE 2... A deepening upper level trough will approach the region from the west Thursday night as the trough becomes negatively tilted by Friday. Low pressure is expected to track from the Upper Great Lakes into Quebec with various deterministic guidance showing the low potentially strengthening to around 980 hPa. A warm front lifts north of the region Thursday afternoon putting us in the system's warm sector for Thursday night. Plenty of moisture transport from the Gulf and western Atlantic will aid in a widespread rainfall starting later Thursday night (start time later than previous forecasts) and continuing into Friday morning. The system's cold front then crosses the region on Friday bringing in much colder weather for Friday afternoon and Friday night. As temperatures fall near and below freezing behind the front, precipitation will mix with or change over to snow, first across the higher elevations and later across the valleys. Precipitation then begins to taper off Friday night as the upper trough departs and surface high pressure returns.

Latest NBM mean QPF amounts range from 0.75 to 1.50 inches across the region. While some rises on area rivers, creeks and streams is expected, no flooding is expected to occur at this time.

The strong wind field around this system (i.e. 50-70 kt low- level jet winds) will increase the potential for gusty southerly winds on Thursday night and westerly winds on Friday. Wind gusts greater than 40 mph will likely be favored along the Taconics into western New England for Thursday night with more widespread potential for 40+ mph gusts on Friday across much of the region, especially the Mohawk Valley, Capital District, eastern Catskills and Berkshires. Wind advisories may be needed later in time if confidence on these wind gusts continues to increase.

In addition, there is the potential for any areas of standing water to freeze up by Friday night as temperatures continue to fall well below freezing, falling back to the teens and low 20s with single digits across the Adirondacks.

KEY MESSAGE 3... On the heels of the late week storm, a clipper system is expected to track north of our area from the Upper Great Lakes into Quebec next weekend. Isentropic lift ahead of an approaching warm front may result in a period of precipitation which may fall as mostly snow Saturday night into Sunday. The track of this low will determine where the higher chances for precipitation set up. At this time, the higher chances are for areas along and north of I-90 but may change in future forecast updates. Additional snow showers or a valley rain/snow mix is possible Sunday afternoon into Sunday night before drier weather returns by Monday.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Through 18z Wednesday...Outside of very low potential of MVFR ceilings late in the period at KGFL, VFR conditions are primarily expected at the terminals over the next 24 hours. Light winds primarily out of the south/southwest under 10 kts this afternoon will become light & variable tonight, with the exception of KALB which will continue to see sustained winds out of the south around 10 kts. LLWS was maintained at KGFL/KPSF/KPOU beginning this evening as the low-level jet and 2 kft winds increase to around 35-40 kts. This threat will diminish Wednesday morning as surface winds increase out of the south around 10 kts. Gusts around 20 kts are also expected at KALB.

Outlook...

Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Low Operational Impact. Breezy. NO SIG WX. Thursday Night: High Operational Impact. Breezy. Definite RA. Friday: High Operational Impact. Breezy. Definite RA...SN. Friday Night: Moderate Operational Impact. Breezy. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: Moderate Operational Impact. Chance of SN. Sunday: Low Operational Impact. Slight Chance of RA...SN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.